Structural Revision of Garcinielliptin Oxide and Garcinielliptone E

J Nat Prod. 2020 Jun 26;83(6):2041-2044. doi: 10.1021/acs.jnatprod.0c00306. Epub 2020 Jun 4.

Abstract

Previously, Lin et al. reported the isolation and structural determination of two triterpenoids, garcinielliptin oxide (GO) and garcinielliptone E (GE). Their unusual structural features, which remained unparalleled in subsequent decades despite the intervening discovery of hundreds of other polycyclic polyprenylated acylphloroglucinols (PPAPs), caused us to question the originally assigned structures, so GO was reisolated from Garcinia subelliptica, and its NMR spectra were reacquired. In this Note, we revise the structures of GO and the related GE via NMR analysis, biosynthetic considerations, and chemical conversion. Garcinielliptone T, a new PPAP, was also isolated and characterized. GO exhibited weak inhibitory activity against acetylcholinesterase with an IC50 value of 20.7 μM.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cholinesterase Inhibitors / pharmacology
  • Garcinia / chemistry
  • Magnetic Resonance Spectroscopy
  • Molecular Structure
  • Oxides
  • Plant Extracts / chemistry
  • Plant Leaves / chemistry
  • Spectrometry, Mass, Electrospray Ionization
  • Triterpenes / chemistry*

Substances

  • Cholinesterase Inhibitors
  • Oxides
  • Plant Extracts
  • Triterpenes
  • garcinielliptone